Salesmen's motivational acronym for "Always Be Closing", the traditional slogan that emphasizes the need to be continually moving the customer towards agreement and action within sales discussions.

(Blake flips over a blackboard which has two sets of letters on it: ABC, and AIDA.)
Blake: A.B.C. A-always, B-be, C-closing. Always be closing! Always be closing! A.I.D.A. Attention, Interest, Decision, Action. Attention -- do I have your attention? Interest -- are you interested? I know you are because it's fuck or walk. You close or you hit the bricks! Decision -- have you made your decision for Christ?!! And action. A.I.D.A. Get out there! You got the prospects coming in; you think they came in to get out of the rain? Guy doesn't walk on the lot unless he wants to buy. Sitting out there waiting to give you their money! Are you gonna take it? Are you man enough to take it?
--Glengarry Glen Ross